Typically, a speaker is a device for converting an electric signal into a voice signal and that is applied to a variety of acoustic equipment. In particular, since portable electronic equipment such as PDAs (personal digital assistants), notebook computers, communication terminals, portable terminals, MP3 players, netbooks, and so on, have a tendency of being made thin in thickness, the portable electronic equipment is made small in size and is provided with a thin micro-speaker.
Micro-speakers require an ultra-light/super-slim structure so as to be applied to the portable electronic equipment, and need to be able to regenerate a sound source as the original sound with high power and broadband.
These micro-speakers use respective thin film diaphragms having the lightweight and flexibility to give high-power and slim-type. These thin film diaphragms should be made thin in thickness thus enabling flexible movement, and should be designed to have wavy wrinkles, thereby increasing the entire surface area of each of the diaphragms.
However, as the amplitude of vibration of the thin film diaphragm grows, the pressure exerted on the diaphragm increases. Thus, the thin diaphragm is prone to breakage, and has the difficulty in making wavy wrinkles thereon.
As disclosed in Korean Patent Registration No. 10-0834075 (May 26, 2008), a conventional speaker diaphragm is configured to include: a polyethylene-based mesh plate having a number of holes; and a thermoplastic elastomer film that is thermally compressed on the polyethylene-based mesh plate, to thus block a plurality of holes formed on the polyethylene-based mesh plate, thereby realizing strong wear-resistance and lowering the minimum resonance frequency even with the thin film.
However, since the conventional speaker diaphragm is produced by thermal compression of the mesh plate and the thermoplastic elastomer film, there is a limit in thinning the speaker diaphragm. In addition, the speaker diaphragm may be deformed during performing thermal compression, and the manufacturing process is complicated.